Nail-string machine



S. M. CUTTER.

NML STRING MACHINE.

AFPLlCATlON FILED AUG 10; 1916 1,897,204, Patented Nov. 15 1921.

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NAIL STRING MACHINE.

. APPLICATION FILED AUG 10, 1916.

1,397,204. Patented Nov. 15, 1921 4 SHEETSSHEE1 2.

S M. CUTTER.

NAIL STRING MACHINE.

APPLICATION FILED AUG 10.1916

Patented Nov. 15; 1921..

4 SHEETSSHEEI 3,

S. M. CUTTER.

NAIL STRING MACHINE.

APPLICATION FILED AUG. 10, 1916. 1,397,204. Patented Nov. 15, 19210 III I: III. .L'I.

i" u I I la) I e 1'8 'VMEM Jam M SOLOMON M. CUTTER, OF HARTFORD, CONNECTICUT, ASSIGN'OR TO CAJPEWELL HORSE NAIL COMPANY, OF HARTFORD, CONNECTICUT, A CORPORATION OF CONNECTICUT.

NAIL-STRING MACHINE.

Specification of Letters Patent.

Patented Nov. 1L5, 1921.

Application filed August 10, 1916. Serial No. 114,110.

To all whom it may concern:

Be it known that I, SOLOMON M. CUTTER, a citizen of the United States, residing at Hartford, Connecticut, have invented the following described Improvements in Nail- String Machines.

The invention is an improved machine for producing nail strings or continuous strips of connected nail blanks used in the manufacture of horse nails and intended to be supplied to other machines which sever the blank from the stock and finish them by shaping their heads and setting, scarting and pointing their shanks. The object of the invention is the attainment of greater compactness of the structure, higher operating speed and superior control and accuracy of the die rolling operation and also other objects. all of which will be apparent to those skilled in the art in connection with the four sheets of drawings constituting part here- "of and wherein-- Figure 1 is a side elevation partly in section of the preferred form of my invention;

Fig. 2 a detail of the adjustment between one of the die rolls and its drive inion;

Fig. 3 a typical cross-section tn'ough the die rolls at one of the passes;

Fig. 4 a horizontal plan partly in section of the lower die roll with the stock in dicated in position thereon and other parts shown in cross-section; I

Fig. 5 is a cross-section of the friction retracting mechanism of which there is one for each pass through the die roll;

Fig. 6 is a cross-section through the die rolls in the line of the pass between the first pair of die sets;

Fig. 7 is a similar cross-section at the line of the pass of one of the later pairs of die sets; and

Fig. 8 (on Sheet 3) is a partial plan of the retrac-tor bracket and stop rail 16.

The machine frame of suitably massive design carries two strong roll housings 1 firmly fixed thereon and containing the bearings for the upper and lower die rolls 2 and 3. The bearings for the upper roll are adjustable toward the lower roll againstthe pressure of the bearing springs by means of the set screws shown and, as generally customary in the art of rolling mills, these screws are intended to be geared together by means not shown in the drawings to. equalize the adjustment of the two upper bearings and kee the rolls thereby strictly in parallelism. he two die rolls may carry upon them and between the said housings all of the dies necessary to reduce the rod stock into a finished nail string and these dies are number of stages if desired.

In Fig. 1 the several groups are identified by the dotted division lines marked I, II, TH, etc. at the top of the figure and each group comprises a set of dies ordie-cavities 4 distributed about the periphery of the upper roll at its particular zone and a corresponding set of cooperating dies or die cavities 4 similarly distributed around the same zone of the lower roll, the dies of the two sets being correlated so as to come properly into registry as the rolls rotate. While the number of dies or die cavities in each set may obviously be varied, the present machine has six dies in each set on each roll excepting the first group which has seven as presently explained, and all the dies 0 each set are duplicates in shape and size so that one revolution of the rolls effects six (or seven) successive and'identical operations upon the stock all representing one stage in the process of its reduction to finished shape. The group of dies or die cavities constituting the set at the left hand end of the die rolls in Fig. 1 and marked I produces the initial state of formation of the stock, the group marked 11 produces the second stage, "the group III the third, and so on, and the series of groups is arranged to roll the stock alternately on its edges and the flat sides, that is to say, groups I, III, V, andVIT roll the' stocks edgewise and the intermediate groups roll it flatwise, The rod stock is sent through the passes of the eight groups in continuous form and substantially in the path of a helix, the axis of which is parallel to the rolls. It is introduced first into the pass of group No.1 and on emerging from the delivery side of that group is conducted rearwardly around and over the top roll to the entrance slde of the group H; from delivery side of group H it is again turned upwardly and over the top roll into the path of the group HT and from the delivery of the latter'into th pa h of group IV and so on until it emerges from the delivery side of the last group of dies. The helical spires of thestock intervening between the die groups extend vertically upward and above the top roll to such height as may be necessary to avoid too sharp curvature and also to accommodate, without permanent distortion the quarter twist in the stock which permits it to enter each pass alternately on its edge and fiat side as above explained. Extending upwardly in this manner, the said spires are out of the way and do not obstruct access to the die mechanism but are subject to observation by the operator. One or more longitudinal rods or racks 5 mounted on posts (3 rising from the roll housings may be used to guide and steady the upstanding spires so that they do not interefere'withone another when the rolls are in action.

As the die-rolled stock emerges from each pass it passes under a guide roller 7 individual to that pass and between said roller and a guide block 8 which is channeled with the proper sectional contour to receive and guide it properly. All these blocks and the guide rollers thereon are carried by a common bracket 9 planted on the delivery side of the die rolls. ()n the entrance side of the rolls the stock is introduced into the several passes under the control of a series of friction retractors all of which are duplicates except for the shape of the stock grooves or channels therein which are made to conform to the shape ofthe stock they receive and control, and all of the retractors are mount ed upon a single frame bracket 10 planted on the main bed plate with its upper part prlotruding inwardly toward the bite of the ro ls.

This bracket 10 is formed of a solid base part 11 and a series of upstanding parallel websor walls 12, the upper flush surfaces of which form a table surface interrupted by the parallel slots 13 intervening between them, and one of said slots is disposed substantially in the vertical plane of the pass of each die group on the die rolls and forms a guiding slide-way for the friction retractor of that group.

Each retractor comprises a lower jaw or base member 14 resting on the margins of its slot 13 and provided with a depending rib within the slot and constituted in the present case by two alined T-shaped lugs 15 the heads of which engage the under margins of the slot so that the base of the retractor is thus confined to slide in a fixed path toward and from the die rolls. The retractor base is introduced into the slot from its outer end and confined therein by the bar 16 secured across the ends of the slots and which carries the screws 17 to limit the outward movement of the retractors. Such outward movement 1s caused by a spring or weight acting through a bell crank 19, the working arm of which engages each retractor base between the two lugs 15 thereof above referred to. The bell cranks for the several retractors are mounted in the slots 13 on a common fulcrum shaft carried by the upstanding walls 12 and their weighted arms extend laterally through and beyond the edge of the bracket for attachment to the weights 18 hung below the bed. The set screws 20 threaded in a cross piece of the bracket immediately above the weight arms of the bell crank serve as adjustable stops to limit the inward or forward motion of the retractors.

The retractor base 14 is longitudinally grooved with a channel of appropriate cross sectional shape to conform to and guide the stock in the particular stage in which it enters the die roll pass to which the retractor belongs and at its rear or outer end it carries a roller 21 which guides the stock into the groove as will be evident. By means of six upstanding posts 23 (see also Fig. 4) mounted three on each side, the retractor base 14 carries rigidly upon it a top plate 22, there by forming between said base posts and top plate, a cage or housing for the movable jaw 21 of the retractor which has a rib 25 entering the stock channel in the base or lower jaw 1t and pressed against the stock therein by means of two strong coil springs 26 contained in bores in the jaw 24 and thrusting against the under face of the cover 22. The frictional pressure thus exerted on the stock passing through the retractor can be relieved when desired by means of the cam lever 27 which is fulcrumed to a lug 28 on :the movable jaw 24 whichprojects through a hole in the top plate 22. 1 The cam shaped end of the lever 27 engages the cover 22 to lift the jaw 24 against the springs and, thereby removes the pressure upon the stock. Said handles are used for this purpose and to open the stock channels when the stock is being first introduced into the retractors but when the machine is in operation all the levers stand in an upright or inoperative position as indicated in the drawings. The retractor lower jaws 14 appear in the plan view of Fig. 4 with the top plates thereof and the spring-pressed jaws removed, in

respect to the zones I to VI. In zone VII the spring pressed jaw is shown in place without the top plate and in pass VIII the plate is shown applied. I I

By reason of its frictional engagement with the stock, the retractor is pulled forwardly by the rotation of the die rolls but only to the extent permitted by the setting of its stop screw 20 and after the engagement of the bell crank with said screw the stock is pulled forwardly through the jaws of the then stationary retractor until the die blocks let go of the blank whereupon the eer/sea retractor acts to withdraw the stock to a rearward position determined by the screw 17 and wherein the next blank to be rolled will be held in position to be engaged properly by the next pair of cooperating dies thus assuring registry of the successive blanks with the successive pairs of dieblocks of each zone.

In the case of the first pass the seven die cavities are formed in one die block 30 on each roll or in successively contiguous arrangement altogether occupying somewhat less than 180 of the circumference of each I die roll, the spaces between the ends of the blocks constituting a clearance in which no action takes place and in which the stock is free from the rolls. A single rotation of the die rolls forms seven rough nail blanks on the stock as will be plain from Fig. 6 and on the completion of the seventh blank the retractor acts to retract the stock a distance which will bring the head part of the seventh blank 32 into a position where it will be encountered by the head cavity of the forward pair of die blocks on the next rotation and again be drawn forwardly thereby. The seventh blank of the first rotation thus becomes the first blank of the second and is preferably only partially formed by the seventh die, so thaton re-rolling in the first, it will feed properly and receive the same degree of compression and exactly the same shape as the others. Its withdrawal for engagement with the first die block in themanner just stated .is for the purpose of insuring accurately uniform spacing of the rudimentary blanks emerging from the first pass, and giving the advancing first cavities a proper purchase on the stock (otherwise smooth) so that they may draw it forward. This means of feeding and spacing the blanks of the initial pass is an important feature of my invention, being obviously susceptible of application to continuous blank rolling mills of different character from that shown. Fig. 6 illustrates the pair of forward die cavities in the act of engaging the seventh blank of the preceding rotation and it will be observed that the retractor is engaged at that moment by its stop screw 17. It advances as the stock advances, remaining in a forward position until the next six blanks have been rolled, whereupon it recedes again into contact with its set screw 17 The drawings do not profess to show the relief of the seventh die cavity, which is slight. Each rotation of the die blocks 30 thus delivers six rudimentary nail blanks into the guideblock '8 to form the first spire of the stock,

The die sets of groups H to VH1 are constituted of individual die blocks 4, secured in place between longitudinal ribs 33 (Fig. 3) formed on the die rolls and locked therein byineans of the wedge-shaped heads of a set of screws 34, (Fig. 7) which clamp the dies firmly upon the die rolls or upon the shims 35 inserted under them where necessary. By this arrangement a clearance space occurs between each of the six successively-acting pairs of dies of each group, and such clearances are utilized in the same manner as the larger clearance of group it for the purpose of permitting the retractors to impart a necessary retrograde movement to the stock'to enable each successive pair of dies to register with the succeeding nail blanks. Thus, as shown in Fig. 7, one pair of dies is ust finishing the rolling operation upon the blank marked 36 having drawn .the retractor forwardly. Immediately that the clearance spaces in rear of these dies registers withthe stock, the retractor will recede to its screw 17 and thereby bring the head of the next blank 37 into a position wherein it will be encountered by the head cavity 37 of the next pair of dies, to be again drawn forwardly and so on. Between each die rolling operation the retractors recede for this purpose and each complete rotation of the die rolls results in the delivery of six blanks into the spire of stock which goes, to the next group, and each rotation draws six blanks through the retractors so that the advance of the stock through the several passes of the machine is independent of the attenuation imparted to it at any of the passes. The spires between the passes are thus maintained of constant size and any or all of the die blocks can be adjusted as circumstances may require without changing the feed or requiring any other adjustmeht. v

As will be observed in the plan view of Fig. 4, the die cavities in each longitudinal row of die blocks in the die rolls are offset in the circumferential direction, that is to I say the head cavities of the blocks in the different zones are disposed in different radial planes and such arrangement serves to distribute the load on the die rolls so the moment of maximum pressure between one pair of dies does not coincide with the maximum pressure of any other pair, and there by provides a .more continuous action and many obvious advantages incidental thereto, and being of particular service in allowing the use of less massive gear trains for driving the rolls. lln the present case the lower die roll is driventhrough its extended shaft by a gear 38 and a pinion 39 (Fig. 3) carried by the main power shaft 40. The opposite end of the lower roller carries a .pinion 41 by which it drives the pinion a2 of the upper die roll. The latter pinion however is adjustably secured to the shaft of the die roll 2 in order that the die cavities on the upper and lower rolls may be set for accurate registry. The detail of the adjustment is shown in Fig. 2. The pinion 42 carries the lugs 43,0verhanging the abutment faces of a collar 44 on opposite sides of the shaft, the collar being firmly keyed to said shaft. The adjustment screws 45 thrust against the said faces and may be changed as required to alter the angular position of the die roll 2 with reference to the other roll. 7

The operation of the embodiment of the invention illustrated in the drawings may be restated as follows:

The stock which is in the form of a continuous strip is entered edgewise into the pass of the rolls at the left of the machine where the first zone or group of dies is located. On the way, it passes through the channel in the first retractor 14, the friction plate 24 of which is raised for that purpose by depression of the corresponding lever 27, the lever being returned to vertical after the stock has entered the pass. As the stock is drawn forward by the rotation of the rolls, corresponding dies on opposite rolls act upon it giving it the initial shaping effect and at the same time the retractor 14, by virtue of friction with the stock, is drawn forward until the lower arm of bell crank lever 19 strikes the set screw 20, and

thereafter the stock is pulled forward through the jaws of the then stationary retractor, which, since the dies of the first zone succeed each other without intermediate clearances, remains in its forward position until the sto k has been impressed by the seven pairs 0 dies constituting the first zone and the die blocks 30 let go of the stock, whereupon the retractor carrying the stock with it is drawn back through the action of the corresponding weight 18, a distance determined by the position of the set screw stop 17 with which the lugs 15 coact. Since the first group of dies contains an extra pair, the seventh, which produces, a rudimentary first stage formation, the stock is readily gripped by the die rolls as they begin the next revolution, the seventh and rudimentary impression of the first revolution being fed back into the first pass at the beginning of the second revolution and thus constituting the first ofthe second set of first stage nail formations.

In all the zones except the first the retractors withdraw the stock after each impression instead of at the end of the whole series, the clearance between successive dies releasing the stock. This insures an accurate feed and avoids any waste of the stock since successive nails adjoin each other.

Leaving the first pass, the stock moves under the roller 7 and advances in a sub- Stantially helical ath over guides 5 and through the secon retractor to the pass between the two sets of dies of the second group, being given a quarter turn between the two passes so that the dies of the second group act on its flat side. This operation is repeated in the further passage of the stock from the second pass through the third, fourth, fifth and successive passes, the quarter turns being alternately in opposite directions, until the completed nail string issues from the last pass (VIII in the machine shown).

Claims:'

1. A machine for die-rolling nail strings comprising a pair of (lie-rolls having groups of cooperating dies circumferentially disposed in successive zones thereon and adapted to reduce a continuous rod stock to nail string form, each zone representing one of the successive stages in the reduction of rod stock to nail string form, and means for directing the said continuous stock successively through the series of passes formed by said groups of dies.

2; A machine for die-rolling nail strings comprising a pair of die-rolls having coopcrating die-cavities circumferentially disposed in successive zones thereon, the cavities in each zone representing one of the successive stages in the reduction of the stock to nail string form, and means for directing continuous rod stock successively through the passes of the said die cavities, the path of said stock through said passes being substantially in the direction of a helix, with its axis parallel with the axes of said die-rolls.

3. A machine for die-rolling nail strings comprising a pair of cooperating die-rolls geared to rotate together and having diecavities disposed in successive zones along them, the cavities of each zone representing one of the successive stages in the reduction of rod stock to nail string form, and means for directing continuous rod stoclp succes sively through the passes of the die-cavities in each of said zones and around one of'said rolls with the stock between said zones upstanding in substantially vertical positions above said die-rolls.

4. A machine for die-rolling nail strings comprising a single pair of die-rolls journaled in housings at the ends thereof and having cooperating die-cavities disposed in successive zones along said rolls between the housings thereof, the cavities of each of said zones representing successive stages in the reduction of the stock, and means whereby continuous rod stock is directed successively through the passes of the die-cavities in each of said zones and around the axis of one of saiddie rolls.

5. A'machine for die-rolling nail strings comprising a pair of die-rolls each provided with groups of cooperating die-cavities disaaaaaoe successive stage in the reduction of the stock to nail string form, and means whereby continuous rod stock is advanced through the passes of each of said groups and simultaneously operated on by all of them.

6. A machine for die-rolling continuous rod stock comprising a pair of cooperating die rolls each carrying groups of die blocks disposed in successive zones along the same and adapted to reduce said stock to nail string form, each group comprising a set of die-blocks on each roll circumferentially spaced apart thereon with intervening clearance spaces and means for directing said rod stock successively through the passes of each group of die cavities and into registry with the die blocks thereof.

7. A machine for die-rolling continuous rod stock comprising a series of sets of die blocks rotating on a common axis and cooperating with a corresponding series of setsof die blocks, each of said sets having clearance spaces between the blocks thereof and means for conducting the stock successively into the passes formed between sald die sets, said means acting also to register the partially formed blanks thereof with the die cavities.

8. A die-rolling machine comprising a series of rotary the sets arranged to operate successively on a continuous rod stock passed therethrough, in combination with means for guiding the partly rolled stock into registry with said successive die sets comprising a stock-engaging member automatically movable toward and from said (he sets.

9. The combination with a series of rotary die sets arranged to operate successively on a continuous rod stock, of a series ofstock retracting members engaging the stock and controlling the engagement thereof with said die sets.

10. The combination with a series of rotary die sets arranged to operate successively on a continuous rod stock, of a series of stock retracting members provided with stock channels engaging the stock and guiding it into proper registering engagement with the die sets.

11. The combination with a series of rotary die sets arranged to operate successively on a continuous rod stock, of a series of stock retracting members, each having a friction grip upon the stock and controlling the engagement of the same by the die sets.

12. The combination with a series of rotary die sets arranged to operate successively on a continuous rod stock, of a series of slideways opposed to the entrances of each pair of die sets and a series of friction stock retractors mounted on said slideways, and means for urging said retractors in a rearward direction with respect to the course of the stock therethrough:

13. In a die-rolling machine, the combination of a pair of die rolls bearing sets of cooperating die blocks arranged in zones thereon. said sets of die blocks being adapted to operate successively on continuous rod stock passed therethrough, and a series of guides controlling the entrance of the stock to the passes between said die sets provided with means for frictionally retarding the forward advance of the stock therethrough.

14- In a die-rolling machine, the combination of a. pair of die rolls bearing sets of cooperating dies adapted to operate successively on continuous rod stock, and a series of movable friction guides controlling the entrance of the stock to the passes between said die sets and adapted to retract the stock to predetermined positions with respect to the cavities of the dies.

15. The combination with a pair of die rolls bearing cooperating sets of dies peripherally spaced thereon with clearances intervening between them, of guiding means for the stock whereby the stock may advance during the cooperation of opposing dies and adapted to retract the stock during the opposition of said clearances.

16. The combination with a pair of die rolls bearing cooperating sets of dies peripherally Spaced thereon with clearances intervening between them, guiding means for the stock adapted to retract the same when the clearances are in opposition, and means for limiting the retracting motion of said guiding means and stock.

17. A die-rolling machine comprising a series of cooperating die sets respectively carried on upper and lower die rolls and each set comprising an equal number of die blocks with intervening clearances, the die blocks of each set in the series representing successive stages in the reduction of the rod stock and means for guiding said stock in a substantially helical path through said die sets whereby each rotation advances the stock according to the number of die blocks in each set.

18. In a die-rolling machine the combination with the power shaft, of cooperating die rolls bearing series of die sets adapted for successive operation on continuous rod stock, the die cavities in said dies being suc-' cessively advanced circumferentially with respect to the position of the Power shaft to distribute the load thereon.

19. In a die-rolling machine a die roll provided with longitudinal ribs adapted to contain sets of die blocks in diflerent zones therealong, cooperating die-rolling means, and means for directing continuous rod stock through the passes of the die 'setsof each zone.

20. In a die-rolling machine a die roll provided with longitudinal ribs and sets of die blocks secured in place between the same in successive zones along said roll, the die blocks in each zone having die cavities representing successive stages in the reduction of the stock and successively advanced circumferentially with respect to each other to distribute the load on said roll.

21. A die-rolling machine, adapted to form continuous rod stock into a continuous strip of die-rolled blanks and including a pair of rolls carrying cooperating die sets, each set comprising aplurality of die cavities, and stock guiding means whereby the last rolled blank in each die rolling operation is caused to register with the next following die cavities to be rolled again thereby.

22. In a die rolling machine for forming smooth stock into a strip of die-rolled blanks, two cooperating die sets, each comprising contiguous die-cavities with a circumferential clearance between the last-acting and the first-acting thereof, and means for presenting the blank from the last-acting cavities to the first-acting cavities in the next following die-rolling operation.

23. In a die-rolling machine for forming smooth stock into a strip of die-rolled blanks, two cooperating die sets, each comprising adiacentv die-aavities, the last-acting cavity being relieved to only partially shape the blank therein, and means for presenting said partially-rolled blank to the first-acting cavity in the next following die-rolling operation.

24:. In a die-rolling machine adapted to reduce continuous rod stock into a continuous strip of die-rolled blanks and comprising a series of groups of cooperating die sets for such purp0se, means for effecting the first die-rolling operations comprising a series of successively acting die cavities and stock Euidinmeans whereby the blank formed y the ast of said cavities is caused to register with the first of the next following cavities of said group.

25. In a die-rolling machine adapted to reduce continuous rod stock into a string of connected blanks and comprising a pair of die rolls, the combination of a set of die cavities on each roll, said cavities being juxtaposed without clearances between them and means whereby the blanks formed by adapted to receive the plain rod stock and to.

effect the first stage of said reduction.

27 A die-rolling machine pairs of die rolls having sets of dies in difcomprising ferent zones thereon, gears connecting said die rolls, and means whereby one of said rolls is angularly adjusted with respect to said gears.

28. A die-rolling machine comprising a series of pairs of cooperating annular sets of dies rotating about'a common axis and at the same speed of rotation, the first pair having means to supply it with continuous smooth rod stock and operating to deliver said stock with equally spaced blanks therein to the second pair of die sets.

In testimony-whereof, I have signed this specification.

SOLOMON M. CUTTER. 

